Buggy code:
class ASTConverter { protected AST ast ; protected Comment [ ] commentsTable ; char [ ] compilationUnitSource ; int compilationUnitSourceLength ; protected DocCommentParser docParser ; protected boolean insideComments ; protected IProgressMonitor monitor ; protected Set pendingNameScopeResolution ; protected Set pendingThisExpressionScopeResolution ; protected boolean resolveBindings ; Scanner scanner ; private DefaultCommentMapper commentMapper ; public ASTConverter ( Map options , boolean resolveBindings , IProgressMonitor monitor ) { } protected void adjustSourcePositionsForParent ( Expression expression ) { } protected void buildBodyDeclarations ( TypeDeclaration typeDeclaration , AbstractTypeDeclaration typeDecl ) { } protected void buildBodyDeclarations ( TypeDeclaration enumDeclaration2 , EnumDeclaration enumDeclaration ) { } protected void buildBodyDeclarations ( TypeDeclaration expression , AnonymousClassDeclaration anonymousClassDeclaration ) { } void buildCommentsTable ( CompilationUnit compilationUnit , int [ ] [ ] comments ) { } protected void checkAndAddMultipleFieldDeclaration ( FieldDeclaration [ ] fields , int index , List bodyDeclarations ) { } protected void checkAndAddMultipleLocalDeclaration ( Statement [ ] stmts , int index , List blockStatements ) { } protected void checkCanceled ( ) { } protected void completeRecord ( ArrayType arrayType , ASTNode astNode ) { } public ASTNode convert ( AbstractMethodDeclaration methodDeclaration ) { } public ClassInstanceCreation convert ( AllocationExpression expression ) { } public Expression convert ( AND_AND_Expression expression ) { } private AnnotationTypeDeclaration convertToAnnotationDeclaration ( TypeDeclaration typeDeclaration ) { } public ASTNode convert ( AnnotationMethodDeclaration annotationTypeMemberDeclaration ) { } public SingleVariableDeclaration convert ( Argument argument ) { } public Annotation convert ( org . eclipse . jdt . internal . compiler . ast . Annotation annotation ) { } public ArrayCreation convert ( ArrayAllocationExpression expression ) { } public ArrayInitializer convert ( org . eclipse . jdt . internal . compiler . ast . ArrayInitializer expression ) { } public ArrayAccess convert ( ArrayReference reference ) { } public AssertStatement convert ( org . eclipse . jdt . internal . compiler . ast . AssertStatement statement ) { } public Assignment convert ( org . eclipse . jdt . internal . compiler . ast . Assignment expression ) { } public TypeDeclaration convert ( ASTNode [ ] nodes ) { final TypeDeclaration typeDecl = new TypeDeclaration ( this . ast ) ; typeDecl . setInterface ( false ) ; <START_BUG> int nodesLength = nodes . length ; <END_BUG> for ( int i = 0 ; i < nodesLength ; i ++ ) { ASTNode node = nodes [ i ] ; if ( node instanceof Initializer ) { Initializer oldInitializer = ( ( Initializer ) ( node ) ) ; Initializer initializer = new Initializer ( this . ast ) ; initializer . setBody ( convert ( oldInitializer . block ) ) ; setModifiers ( initializer , oldInitializer ) ; initializer . setSourceRange ( oldInitializer . declarationSourceStart , ( ( ( oldInitializer . sourceEnd ) - ( oldInitializer . declarationSourceStart ) ) + 1 ) ) ; convert ( oldInitializer . javadoc , initializer ) ; typeDecl . bodyDeclarations ( ) . add ( initializer ) ; } else if ( node instanceof FieldDeclaration ) { FieldDeclaration fieldDeclaration = ( ( FieldDeclaration ) ( node ) ) ; if ( ( ( i > 0 ) && ( ( nodes [ ( i - 1 ) ] ) instanceof FieldDeclaration ) ) && ( ( ( ( FieldDeclaration ) ( nodes [ ( i - 1 ) ] ) ) . declarationSourceStart ) == ( fieldDeclaration . declarationSourceStart ) ) ) { FieldDeclaration currentFieldDeclaration = ( ( FieldDeclaration ) ( typeDecl . bodyDeclarations ( ) . get ( ( ( typeDecl . bodyDeclarations ( ) . size ( ) ) - 1 ) ) ) ) ; currentFieldDeclaration . fragments ( ) . add ( convertToVariableDeclarationFragment ( fieldDeclaration ) ) ; } else { typeDecl . bodyDeclarations ( ) . add ( convertToFieldDeclaration ( fieldDeclaration ) ) ; } } else if ( node instanceof AbstractMethodDeclaration ) { AbstractMethodDeclaration nextMethodDeclaration = ( ( AbstractMethodDeclaration ) ( node ) ) ; if ( ( ! ( nextMethodDeclaration . isDefaultConstructor ( ) ) ) && ( ! ( nextMethodDeclaration . isClinit ( ) ) ) ) { typeDecl . bodyDeclarations ( ) . add ( convert ( nextMethodDeclaration ) ) ; } } else if ( node instanceof TypeDeclaration ) { TypeDeclaration nextMemberDeclaration = ( ( TypeDeclaration ) ( node ) ) ; ASTNode nextMemberDeclarationNode = convert ( nextMemberDeclaration ) ; if ( nextMemberDeclarationNode == null ) { typeDecl . setFlags ( ( ( typeDecl . getFlags ( ) ) | ( ASTNode . MALFORMED ) ) ) ; } else { typeDecl . bodyDeclarations ( ) . add ( nextMemberDeclarationNode ) ; } } } return typeDecl ; } public Expression convert ( BinaryExpression expression ) { } public Block convert ( org . eclipse . jdt . internal . compiler . ast . Block statement ) { } public BreakStatement convert ( org . eclipse . jdt . internal . compiler . ast . BreakStatement statement ) { } public SwitchCase convert ( CaseStatement statement ) { } public CastExpression convert ( org . eclipse . jdt . internal . compiler . ast . CastExpression expression ) { } public CharacterLiteral convert ( CharLiteral expression ) { } public Expression convert ( ClassLiteralAccess expression ) { } public CompilationUnit convert ( CompilationUnitDeclaration unit , char [ ] source ) { } public Assignment convert ( CompoundAssignment expression ) { } public ConditionalExpression convert ( org . eclipse . jdt . internal . compiler . ast . ConditionalExpression expression ) { } public ContinueStatement convert ( org . eclipse . jdt . internal . compiler . ast . ContinueStatement statement ) { } public DoStatement convert ( org . eclipse . jdt . internal . compiler . ast . DoStatement statement ) { } public NumberLiteral convert ( DoubleLiteral expression ) { } public EmptyStatement convert ( org . eclipse . jdt . internal . compiler . ast . EmptyStatement statement ) { } public EnumConstantDeclaration convert ( FieldDeclaration enumConstant ) { }

Fix:
int nodesLength = ( nodes == null ) ? 0 : nodes . length ;